I have recently rewired my car and fitted an Koso RX1N speedo unit,My Question is ... I'm thinking of fitting the magnets and pick up sensor in the rear brake drum,Koso supply 6 magnets for this unit,should I be using them all ? Also,to have the speedo running currectly it asks for the wheel circumference,If I fit it too the rear drum do I then have to figure out the circumference of the drum ???

Mike

think its just the circumference of the tyre, because it will count 1 turn of the drum as 1 turn of the tyre

Mark the wheel ( I use the valve) and the ground, roll the car ten turns of the wheel , mark the ground , measure between the two marks and divide that measurement by ten to give you a average circumference of the wheel .

That is how we set up spray units at work.

You then have to divide the circumference by the number of magnets, the more magnets the better the response of the speedo unit .



Cheers

Vaughan

[Edited on 24/1/08 by vorn]

I have a Koso part installed. I am planning on installing my sensors into the prop adaptor. There is plenty of meat in my adaptor, and it saves the headache of trying to set it up inside a drum! The complicated bit for me will be working out the correct settings for the gauge to give the correct reading.

I have 4 magnets on the rear of the prop flange, that way i can change diffs and axles to my hearts content and just recalibrate the speedo